/* ═══════════════════════════════════════════════════════════════════════════
 * knowledge.css — shared design system for the Si Math AI Knowledge Center
 * (about.html · how-it-works.html · founder-badge.html · faq.html)
 *
 * Tokens are copied from index.html so the knowledge pages are visually part
 * of the same product rather than a bolt-on microsite. One stylesheet keeps
 * the four pages from drifting apart the way four inline <style> blocks would.
 *
 * Loaded as a same-origin stylesheet, which the site CSP allows under
 * style-src 'self'. No external CSS, no CDN, no webfonts beyond the Google
 * Fonts families the rest of the site already loads.
 * ═══════════════════════════════════════════════════════════════════════════ */

:root {
  --bg: #050a14;
  --bg-elev-1: #0a1224;
  --bg-card: #0c1428;
  --bg-card-hi: #101a32;

  --cyan: #38bdf8;
  --cyan-2: #0ea5e9;
  --cyan-3: #7dd3fc;
  --cyan-bg-soft: rgba(56,189,248,.1);
  --cyan-border: rgba(56,189,248,.28);
  --cyan-border-soft: rgba(56,189,248,.14);

  --purple: #a855f7;
  --purple-soft: rgba(168,85,247,.12);
  --purple-border: rgba(168,85,247,.32);

  --green: #22c55e;
  --amber: #f5b942;

  --text-100: #ffffff;
  --text-200: #dde8f7;
  --text-300: #a8bcd9;
  --text-400: #7a90b2;
  --text-500: #536b8c;

  --border-soft: #1a2540;
  --border-mid: #26334d;

  --r-sm: 10px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 24px;

  --font-display: 'Manrope', system-ui, -apple-system, sans-serif;
  --font-body: 'DM Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;

  --nav-h: 56px;
  --container-x: 18px;
  --section-y: 56px;
  --maxw: 860px;

  --fs-h1: 34px;
  --fs-h2: 25px;
  --fs-h3: 18px;
  --fs-body: 16px;
}

@media (min-width: 768px) {
  :root {
    --nav-h: 64px;
    --container-x: 32px;
    --section-y: 88px;
    --fs-h1: 54px;
    --fs-h2: 34px;
    --fs-h3: 20px;
    --fs-body: 17px;
  }
}

@media (min-width: 1200px) {
  :root { --fs-h1: 62px; --section-y: 104px; }
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }

html {
  background-color: var(--bg);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--nav-h) + 16px);
}

body {
  background-color: var(--bg);
  color: var(--text-200);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

/* Atmospherics — fixed so they never trap scroll. */
.backdrop { position: fixed; inset: 0; background: var(--bg); z-index: -2; }
.bg-grid {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    linear-gradient(rgba(56, 189, 248, .04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, .04) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 20%, #000 30%, transparent 80%);
  mask-image: radial-gradient(ellipse 80% 60% at 50% 20%, #000 30%, transparent 80%);
}

/* ── Skip link: keyboard users should not tab the whole nav ── */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 1100;
  background: var(--cyan); color: #04121f; padding: 10px 16px;
  border-radius: 0 0 var(--r-sm) 0; font-weight: 700;
}
.skip-link:focus { left: 0; }

/* ═══ NAV ═══ */
.k-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  padding: 0 var(--container-x);
  padding-top: env(safe-area-inset-top, 0);
  height: calc(var(--nav-h) + env(safe-area-inset-top, 0));
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px;
  background: rgba(5, 10, 20, .97);
  border-bottom: 1px solid var(--border-soft);
}
.k-nav-logo { display: flex; align-items: center; gap: 8px; text-decoration: none; flex-shrink: 0; }
.k-nav-logo img {
  height: 32px; width: 32px; object-fit: contain; border-radius: 8px;
  border: 1px solid var(--cyan-border); background: var(--bg-elev-1); padding: 2px;
}
.k-nav-logo-text { font-family: var(--font-display); font-size: 15px; font-weight: 700; color: #fff; letter-spacing: -.3px; white-space: nowrap; }
.k-nav-logo-text span { color: var(--cyan); }

.k-nav-links { display: none; align-items: center; gap: 26px; list-style: none; }
.k-nav-links a { color: var(--text-300); text-decoration: none; font-size: 14px; font-weight: 500; transition: color .2s; }
.k-nav-links a:hover, .k-nav-links a[aria-current="page"] { color: #fff; }
@media (min-width: 980px) { .k-nav-links { display: flex; } }

.k-nav-cta {
  display: inline-flex; align-items: center; padding: 8px 16px;
  background: var(--cyan); color: #04121f; border-radius: var(--r-sm);
  font: 700 13px var(--font-body); text-decoration: none; white-space: nowrap;
  transition: background .2s;
}
.k-nav-cta:hover { background: var(--cyan-3); }

/* ═══ LAYOUT ═══ */
.k-main { padding-top: calc(var(--nav-h) + env(safe-area-inset-top, 0)); }
.k-wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--container-x); }
.k-wrap-wide { max-width: 1140px; margin: 0 auto; padding: 0 var(--container-x); }
.k-section { padding: var(--section-y) 0; }
.k-section + .k-section { border-top: 1px solid var(--border-soft); }

/* ═══ BREADCRUMB ═══ */
.k-crumb { padding: 18px 0 0; font-size: 13px; color: var(--text-400); }
.k-crumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.k-crumb a { color: var(--text-400); text-decoration: none; }
.k-crumb a:hover { color: var(--cyan); }
.k-crumb li + li::before { content: "›"; margin-right: 6px; color: var(--text-500); }

/* ═══ TYPOGRAPHY ═══ */
.k-eyebrow {
  display: inline-flex; align-items: center; gap: 7px;
  font: 600 11px/1 var(--font-mono); letter-spacing: 1.4px; text-transform: uppercase;
  color: var(--cyan); background: var(--cyan-bg-soft);
  border: 1px solid var(--cyan-border-soft); border-radius: 100px; padding: 7px 13px;
  margin-bottom: 20px;
}
h1, h2, h3, h4 { font-family: var(--font-display); color: var(--text-100); line-height: 1.18; letter-spacing: -.02em; }
h1 { font-size: var(--fs-h1); font-weight: 800; }
h2 { font-size: var(--fs-h2); font-weight: 800; margin-bottom: 14px; }
h3 { font-size: var(--fs-h3); font-weight: 700; margin-bottom: 8px; }
h4 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }

.k-lead { font-size: clamp(17px, 2.1vw, 21px); color: var(--text-300); line-height: 1.62; }
.k-body p { margin-bottom: 18px; color: var(--text-300); }
.k-body p:last-child { margin-bottom: 0; }
.k-body strong { color: var(--text-100); font-weight: 600; }
.k-body a { color: var(--cyan); text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.k-body a:hover { color: var(--cyan-3); }
.k-body ul, .k-body ol { margin: 0 0 18px 0; padding-left: 22px; color: var(--text-300); }
.k-body li { margin-bottom: 9px; }
.k-body li::marker { color: var(--cyan); }

.k-hr { height: 1px; background: var(--border-soft); border: 0; margin: 36px 0; }

/* ═══ THE POSITIONING STATEMENT — the most repeated block on the site ═══ */
.k-positioning {
  background: linear-gradient(160deg, rgba(56, 189, 248, .07), var(--bg-card));
  border: 1px solid var(--cyan-border); border-radius: var(--r-lg);
  padding: 26px 22px; margin: 30px 0;
}
.k-positioning p {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(16px, 2.2vw, 20px); line-height: 1.5; color: var(--text-100);
  margin: 0 0 8px 0;
}
.k-positioning p:last-child { margin-bottom: 0; }
.k-positioning em { color: var(--cyan); font-style: italic; }
@media (min-width: 768px) { .k-positioning { padding: 32px 30px; } }

/* ═══ CARDS & GRIDS ═══ */
.k-grid { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 700px) { .k-grid-2 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 700px) { .k-grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .k-grid-3 { grid-template-columns: repeat(3, 1fr); } }

.k-card {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-md); padding: 22px;
  transition: border-color .2s, transform .2s;
}
.k-card:hover { border-color: var(--cyan-border-soft); }
.k-card h3 { margin-bottom: 8px; }
.k-card p { color: var(--text-300); font-size: 15px; margin: 0; }
.k-card-icon { font-size: 24px; line-height: 1; margin-bottom: 12px; display: block; }

.k-pillar { border-radius: var(--r-lg); padding: 26px 22px; border-width: 1px; border-style: solid; }
.k-pillar-1 { background: linear-gradient(160deg, rgba(56, 189, 248, .08), var(--bg-card)); border-color: var(--cyan-border); }
.k-pillar-2 { background: linear-gradient(160deg, rgba(168, 85, 247, .08), var(--bg-card)); border-color: var(--purple-border); }
.k-pillar-3 { background: linear-gradient(160deg, rgba(74, 222, 128, .08), var(--bg-card)); border-color: rgba(74, 222, 128, .3); }
.k-pillar-num {
  font: 700 11px/1 var(--font-mono); letter-spacing: 1.2px; text-transform: uppercase;
  color: var(--text-400); margin-bottom: 10px; display: block;
}
.k-pillar ul { padding-left: 18px; margin: 0; }
.k-pillar li { font-size: 15px; margin-bottom: 7px; color: var(--text-300); }

/* ═══ SYSTEM BLOCKS (how-it-works) ═══ */
.k-system {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-lg); padding: 24px 20px; margin-bottom: 18px;
  scroll-margin-top: calc(var(--nav-h) + 20px);
}
.k-system-head { display: flex; align-items: flex-start; gap: 14px; margin-bottom: 14px; }
.k-system-icon {
  width: 44px; height: 44px; flex-shrink: 0; border-radius: var(--r-sm);
  background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border-soft);
  display: grid; place-items: center; font-size: 21px;
}
.k-system-titles { min-width: 0; }
.k-system-titles h3 { margin-bottom: 2px; }
.k-tag {
  display: inline-block; font: 600 10px/1 var(--font-mono); letter-spacing: .8px;
  text-transform: uppercase; color: var(--cyan); background: var(--cyan-bg-soft);
  border: 1px solid var(--cyan-border-soft); border-radius: 100px; padding: 5px 9px;
}
@media (min-width: 768px) { .k-system { padding: 30px 28px; } }

/* ═══ STEP LIST ═══ */
.k-steps { list-style: none; padding: 0; counter-reset: step; }
.k-steps li {
  position: relative; padding-left: 46px; margin-bottom: 22px; counter-increment: step;
}
.k-steps li::before {
  content: counter(step);
  position: absolute; left: 0; top: 0;
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border);
  color: var(--cyan); font: 700 14px/32px var(--font-mono); text-align: center;
}
.k-steps h4 { margin-bottom: 4px; }
.k-steps p { font-size: 15px; color: var(--text-300); margin: 0; }

/* ═══ TABLE ═══ */
.k-table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; margin-bottom: 18px; border-radius: var(--r-md); border: 1px solid var(--border-soft); }
table.k-table { width: 100%; border-collapse: collapse; font-size: 15px; min-width: 520px; }
table.k-table th, table.k-table td { padding: 13px 15px; text-align: left; border-bottom: 1px solid var(--border-soft); vertical-align: top; }
table.k-table th { background: var(--bg-elev-1); color: var(--text-100); font-family: var(--font-display); font-weight: 700; font-size: 14px; }
table.k-table td { color: var(--text-300); }
table.k-table tr:last-child td { border-bottom: 0; }

/* ═══ FAQ ═══ */
.k-faq-controls { display: flex; flex-direction: column; gap: 12px; margin-bottom: 26px; }
.k-faq-search {
  width: 100%; padding: 13px 16px; font: 400 15px var(--font-body);
  background: var(--bg-card); border: 1px solid var(--border-mid);
  border-radius: var(--r-sm); color: var(--text-100);
}
.k-faq-search::placeholder { color: var(--text-500); }
.k-faq-search:focus { outline: 2px solid var(--cyan); outline-offset: 1px; border-color: transparent; }

.k-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.k-chip {
  padding: 7px 13px; border-radius: 100px; cursor: pointer;
  font: 600 12.5px var(--font-body);
  background: var(--bg-card); border: 1px solid var(--border-mid); color: var(--text-300);
  transition: all .18s;
}
.k-chip:hover { border-color: var(--cyan-border); color: var(--text-100); }
.k-chip[aria-pressed="true"] { background: var(--cyan-bg-soft); border-color: var(--cyan-border); color: var(--cyan); }

.k-faq-count { font: 500 13px var(--font-mono); color: var(--text-400); margin-bottom: 16px; }

.k-faq-group { margin-bottom: 34px; scroll-margin-top: calc(var(--nav-h) + 20px); }
.k-faq-group > h2 { font-size: 21px; margin-bottom: 14px; padding-bottom: 10px; border-bottom: 1px solid var(--border-soft); }

details.k-faq {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-md); margin-bottom: 10px; overflow: hidden;
}
details.k-faq[open] { border-color: var(--cyan-border-soft); background: var(--bg-card-hi); }
details.k-faq > summary {
  cursor: pointer; list-style: none; padding: 16px 46px 16px 18px; position: relative;
  font-family: var(--font-display); font-weight: 600; font-size: 15.5px; color: var(--text-100);
  line-height: 1.45;
}
details.k-faq > summary::-webkit-details-marker { display: none; }
details.k-faq > summary::after {
  content: "+"; position: absolute; right: 18px; top: 50%; transform: translateY(-50%);
  color: var(--cyan); font: 400 22px/1 var(--font-mono); transition: transform .2s;
}
details.k-faq[open] > summary::after { content: "−"; }
details.k-faq > summary:focus-visible { outline: 2px solid var(--cyan); outline-offset: -2px; }
.k-faq-a { padding: 0 18px 18px; color: var(--text-300); font-size: 15px; }
.k-faq-a p { margin-bottom: 12px; }
.k-faq-a p:last-child { margin-bottom: 0; }
.k-faq-a a { color: var(--cyan); text-decoration: underline; text-underline-offset: 3px; }
.k-faq-empty { padding: 28px 0; color: var(--text-400); text-align: center; }

/* ═══ FOUNDER ═══ */
.k-founder-hero {
  background: linear-gradient(160deg, rgba(168, 85, 247, .12), var(--bg-card));
  border: 1px solid var(--purple-border); border-radius: var(--r-xl); padding: 28px 22px;
}
.k-slots {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(168, 85, 247, .14); border: 1px solid var(--purple-border);
  color: #e9d5ff; border-radius: 100px; padding: 8px 16px;
  font: 700 13px var(--font-body); margin-bottom: 18px;
}
.k-slots-num { font-family: var(--font-mono); font-size: 16px; color: #fff; }
.k-benefit-list { list-style: none; padding: 0; margin: 0; }
.k-benefit-list li {
  display: flex; gap: 11px; align-items: flex-start;
  padding: 11px 0; border-bottom: 1px solid var(--border-soft); font-size: 15px; color: var(--text-300);
}
.k-benefit-list li:last-child { border-bottom: 0; }
.k-benefit-list .tick { color: var(--green); flex-shrink: 0; font-weight: 700; }
.k-benefit-list strong { color: var(--text-100); }

/* ═══ BUTTONS ═══ */
.k-btn-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.k-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 22px; border-radius: var(--r-sm); text-decoration: none;
  font: 700 15px var(--font-body); transition: all .2s; border: 1px solid transparent;
}
.k-btn-primary { background: var(--cyan); color: #04121f; }
.k-btn-primary:hover { background: var(--cyan-3); transform: translateY(-1px); }
.k-btn-purple { background: var(--purple); color: #fff; }
.k-btn-purple:hover { background: #b975f9; transform: translateY(-1px); }
.k-btn-ghost { border-color: var(--border-mid); color: var(--text-200); background: transparent; }
.k-btn-ghost:hover { border-color: var(--cyan-border); color: #fff; }

/* ═══ ON-PAGE TOC ═══ */
.k-toc {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-md); padding: 20px; margin: 28px 0;
}
.k-toc h2 { font-size: 13px; font-family: var(--font-mono); font-weight: 600; letter-spacing: 1.2px; text-transform: uppercase; color: var(--text-400); margin-bottom: 12px; }
.k-toc ol { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
@media (min-width: 700px) { .k-toc ol { grid-template-columns: repeat(2, 1fr); } }
.k-toc a { color: var(--text-300); text-decoration: none; font-size: 14.5px; display: block; }
.k-toc a:hover { color: var(--cyan); }

/* ═══ CALLOUT ═══ */
.k-note {
  border-left: 3px solid var(--cyan); background: var(--cyan-bg-soft);
  padding: 16px 18px; border-radius: 0 var(--r-sm) var(--r-sm) 0; margin: 22px 0;
}
.k-note p { margin: 0; color: var(--text-200); font-size: 15px; }
.k-note strong { color: #fff; }

/* ═══ FOOTER ═══ */
.k-footer { border-top: 1px solid var(--border-soft); padding: 44px 0 36px; margin-top: var(--section-y); }
.k-footer-grid { display: grid; gap: 26px; grid-template-columns: 1fr; }
@media (min-width: 620px) { .k-footer-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .k-footer-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1140px) { .k-footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr 1fr; } }
.k-footer h3 { font-size: 12px; font-family: var(--font-mono); font-weight: 600; letter-spacing: 1.1px; text-transform: uppercase; color: var(--text-400); margin-bottom: 12px; }
.k-footer ul { list-style: none; padding: 0; }
.k-footer li { margin-bottom: 9px; }
.k-footer a { color: var(--text-300); text-decoration: none; font-size: 14.5px; }
.k-footer a:hover { color: var(--cyan); }
.k-footer-about { font-size: 14px; color: var(--text-400); line-height: 1.65; max-width: 38ch; }

/* The site-wide tagline. Deliberately the last piece of prose on every page:
   the platform's relationship to teaching is the thing we most want a reader —
   and a crawler — to leave with. Source: scripts/_page-shell.mjs (TAGLINE). */
.k-footer-tagline {
  margin: 34px 0 0 0; padding-top: 26px; border-top: 1px solid var(--border-soft);
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(15px, 2vw, 18px); line-height: 1.5;
  color: var(--text-200); text-align: center;
}
.k-footer-tagline + .k-footer-bottom { margin-top: 22px; padding-top: 18px; border-top: none; }

.k-footer-bottom {
  margin-top: 30px; padding-top: 20px; border-top: 1px solid var(--border-soft);
  font-size: 13px; color: var(--text-500); display: flex; flex-wrap: wrap; gap: 8px 18px; justify-content: space-between;
}

/* Focus visibility everywhere — the site is used on shared/school machines
   where keyboard navigation is common. */
a:focus-visible, button:focus-visible, summary:focus-visible, input:focus-visible {
  outline: 2px solid var(--cyan); outline-offset: 2px; border-radius: 4px;
}

/* ═══════════════════════════════════════════════════════════════════════════
 * LEARNING CYCLE DIAGRAM (how-it-works.html)
 *
 * Built from semantic HTML + CSS rather than an image or an inline SVG on
 * purpose: every stage label and description has to be real text so a crawler,
 * a screen reader and an AI system all read the same flow. An <img> of this
 * diagram would be invisible to the systems the knowledge layer exists to
 * inform.
 * ═══════════════════════════════════════════════════════════════════════════ */

.k-flow { list-style: none; padding: 0; margin: 28px 0 0; counter-reset: flowstep; }

.k-flow-item { position: relative; counter-increment: flowstep; }

/* The connector between two stages. Drawn on the item BELOW the gap so the
   last stage never trails a dangling line. */
.k-flow-item + .k-flow-item::before {
  content: "";
  display: block;
  width: 2px;
  height: 26px;
  margin: 0 auto;
  background: linear-gradient(180deg, var(--cyan-border), rgba(56, 189, 248, .5));
}
.k-flow-item + .k-flow-item::after {
  content: "";
  display: block;
  width: 9px; height: 9px;
  margin: -6px auto 6px;
  border-right: 2px solid var(--cyan);
  border-bottom: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.k-flow-node {
  display: flex; align-items: flex-start; gap: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-md);
  padding: 16px 18px;
  transition: border-color .2s, transform .2s;
}
.k-flow-node:hover { border-color: var(--cyan-border-soft); transform: translateX(2px); }

.k-flow-icon {
  width: 40px; height: 40px; flex-shrink: 0;
  border-radius: var(--r-sm);
  background: var(--cyan-bg-soft);
  border: 1px solid var(--cyan-border-soft);
  display: grid; place-items: center;
  font-size: 19px;
}
.k-flow-body { min-width: 0; flex: 1; }
.k-flow-title {
  font-family: var(--font-display); font-weight: 700; font-size: 16px;
  color: var(--text-100); line-height: 1.3; margin-bottom: 3px;
  display: flex; align-items: baseline; gap: 9px; flex-wrap: wrap;
}
.k-flow-num {
  font: 600 10px/1 var(--font-mono); color: var(--cyan);
  background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border-soft);
  border-radius: 100px; padding: 4px 8px; flex-shrink: 0;
}
.k-flow-desc { font-size: 14.5px; color: var(--text-300); line-height: 1.55; margin: 0; }

/* The student's own input opens the loop — mark it as the entry point. */
.k-flow-item.is-start .k-flow-node {
  background: linear-gradient(160deg, rgba(56, 189, 248, .09), var(--bg-card));
  border-color: var(--cyan-border);
}

/* Human support is conditional, not every-cycle — a dashed edge says so at a
   glance without needing the caption to explain it. */
.k-flow-item.is-optional .k-flow-node { border-style: dashed; border-color: rgba(74, 222, 128, .35); }
.k-flow-item.is-optional .k-flow-icon { background: rgba(74, 222, 128, .1); border-color: rgba(74, 222, 128, .3); }
.k-flow-item.is-optional .k-flow-num { color: var(--green); background: rgba(74, 222, 128, .1); border-color: rgba(74, 222, 128, .3); }

/* The outcome the whole loop exists to produce. */
.k-flow-item.is-outcome .k-flow-node {
  background: linear-gradient(160deg, rgba(74, 222, 128, .12), var(--bg-card));
  border-color: rgba(74, 222, 128, .4);
}
.k-flow-item.is-outcome .k-flow-icon { background: rgba(74, 222, 128, .14); border-color: rgba(74, 222, 128, .35); }
.k-flow-item.is-outcome .k-flow-title { color: #bbf7d0; }
.k-flow-item.is-outcome .k-flow-num { color: var(--green); background: rgba(74, 222, 128, .12); border-color: rgba(74, 222, 128, .3); }

/* The loop closes: the outcome feeds the next question. */
.k-flow-loop {
  /* Must wrap. knowledge-graph.html renders a nine-link chain through this
     rule; on a phone a single centred non-wrapping row spilled 291px past both
     edges of the viewport, so the start of the chain was unreachable. */
  display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 10px;
  margin-top: 22px; padding: 14px 18px;
  border: 1px dashed var(--cyan-border); border-radius: 100px;
  background: var(--cyan-bg-soft);
  font: 600 13.5px var(--font-body); color: var(--cyan-3);
  text-align: center;
}

@media (min-width: 768px) {
  .k-flow-node { padding: 18px 22px; }
  .k-flow-title { font-size: 17px; }
}

/* ═══════════════════════════════════════════════════════════════════════════
 * CANONICAL ANSWER BLOCKS (ai-knowledge.html)
 *
 * Quotable, self-contained answers an AI system can lift verbatim. Visually
 * distinct so a human reader understands they are reading the official wording
 * rather than page prose.
 * ═══════════════════════════════════════════════════════════════════════════ */

.k-canon {
  background: var(--bg-card);
  border: 1px solid var(--border-mid);
  border-left: 3px solid var(--cyan);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  padding: 18px 20px;
  margin: 16px 0 26px;
}
.k-canon-label {
  display: block;
  font: 600 10px/1 var(--font-mono);
  letter-spacing: 1.3px;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 10px;
}
.k-canon p { color: var(--text-200); margin-bottom: 12px; font-size: 15.5px; }
.k-canon p:last-child { margin-bottom: 0; }

/* Negative-space guidance: what must NOT be said. Amber rather than red —
   this is a correction, not an error state. */
.k-dont {
  background: rgba(245, 158, 11, .07);
  border: 1px solid rgba(245, 158, 11, .28);
  border-radius: var(--r-md);
  padding: 18px 20px;
  margin: 22px 0;
}
.k-dont h3 { color: #fcd34d; font-size: 16px; margin-bottom: 10px; }
.k-dont ul { margin: 0; padding-left: 20px; }
.k-dont li { color: var(--text-300); font-size: 15px; margin-bottom: 8px; }
.k-dont li::marker { color: var(--amber); }
.k-dont code {
  font-family: var(--font-mono); font-size: 13px;
  background: rgba(245, 158, 11, .12); color: #fde68a;
  padding: 2px 6px; border-radius: 4px;
}

/* ═══════════════════════════════════════════════════════════════════════════
 * EDUCATIONAL KNOWLEDGE HUB (learn.html + learn-*.html)
 * ═══════════════════════════════════════════════════════════════════════════ */

/* Guide cards on the hub index. */
.k-guide-card {
  display: flex; flex-direction: column; gap: 10px;
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-md); padding: 22px; height: 100%;
  text-decoration: none; transition: border-color .2s, transform .2s;
}
.k-guide-card:hover { border-color: var(--cyan-border); transform: translateY(-2px); }
.k-guide-card h3 { color: var(--text-100); margin: 0; font-size: 17.5px; line-height: 1.3; }
.k-guide-card p { color: var(--text-300); font-size: 14.5px; margin: 0; line-height: 1.55; }
.k-guide-meta {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  font: 600 10.5px/1 var(--font-mono); letter-spacing: .9px; text-transform: uppercase;
  color: var(--text-400);
}
.k-guide-topic { color: var(--cyan); }
.k-guide-card .k-card-icon { font-size: 26px; margin: 0; }

/* Hub section grouping. */
.k-hub-group { margin-bottom: 44px; scroll-margin-top: calc(var(--nav-h) + 20px); }
.k-hub-group > h2 { font-size: 22px; margin-bottom: 6px; }
.k-hub-group > .k-hub-sub { color: var(--text-400); font-size: 15px; margin-bottom: 20px; }

/* Key-takeaways box at the head of a guide. */
.k-takeaways {
  background: linear-gradient(160deg, rgba(56, 189, 248, .07), var(--bg-card));
  border: 1px solid var(--cyan-border); border-radius: var(--r-lg);
  padding: 22px; margin: 28px 0;
}
.k-takeaways h2 {
  font-size: 12px; font-family: var(--font-mono); font-weight: 600;
  letter-spacing: 1.2px; text-transform: uppercase; color: var(--cyan); margin-bottom: 14px;
}
.k-takeaways ul { margin: 0; padding-left: 20px; }
.k-takeaways li { color: var(--text-200); font-size: 15.5px; margin-bottom: 10px; }
.k-takeaways li:last-child { margin-bottom: 0; }
.k-takeaways li::marker { color: var(--cyan); }

/* The one place a guide mentions the product. Deliberately restrained: these
   pages exist to teach, and a hard sell inside educational content destroys the
   trust the content was written to earn. */
.k-soft-cta {
  border: 1px dashed var(--border-mid); border-radius: var(--r-md);
  padding: 18px 20px; margin: 30px 0 0; background: rgba(56, 189, 248, .04);
}
.k-soft-cta p { font-size: 14.5px; color: var(--text-400); margin: 0; }
.k-soft-cta strong { color: var(--text-200); }
.k-soft-cta a { color: var(--cyan); }

/* Standing accuracy note on every exam guide. */
.k-verify {
  border-left: 3px solid var(--amber); background: rgba(245, 158, 11, .07);
  padding: 15px 18px; border-radius: 0 var(--r-sm) var(--r-sm) 0; margin: 24px 0;
}
.k-verify p { margin: 0; font-size: 14.5px; color: var(--text-300); }
.k-verify strong { color: #fcd34d; }

/* Educational principles. */
.k-principle {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-lg); padding: 24px 22px; margin-bottom: 18px;
  scroll-margin-top: calc(var(--nav-h) + 20px);
}
.k-principle-num {
  font: 700 11px/1 var(--font-mono); letter-spacing: 1.2px;
  color: var(--cyan); background: var(--cyan-bg-soft);
  border: 1px solid var(--cyan-border-soft); border-radius: 100px;
  padding: 6px 11px; display: inline-block; margin-bottom: 12px;
}
.k-principle h2 { font-size: clamp(19px, 2.4vw, 24px); margin-bottom: 12px; }
.k-principle h3 {
  font-size: 12px; font-family: var(--font-mono); font-weight: 600;
  letter-spacing: 1.1px; text-transform: uppercase; color: var(--text-400);
  margin: 18px 0 8px;
}
.k-principle p { color: var(--text-300); margin-bottom: 12px; }
.k-principle p:last-child { margin-bottom: 0; }
@media (min-width: 768px) { .k-principle { padding: 30px 28px; } }

/* ═══════════════════════════════════════════════════════════════════════════
 * EVIDENCE CENTER (evidence.html · changelog.html · roadmap.html)
 * ═══════════════════════════════════════════════════════════════════════════ */

.k-cap {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-lg); padding: 24px 22px; margin-bottom: 20px;
  scroll-margin-top: calc(var(--nav-h) + 20px);
}
@media (min-width: 768px) { .k-cap { padding: 30px 28px; } }
.k-cap-head { display: flex; align-items: center; gap: 13px; margin-bottom: 16px; }
.k-cap-icon {
  width: 44px; height: 44px; flex-shrink: 0; border-radius: var(--r-sm);
  background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border-soft);
  display: grid; place-items: center; font-size: 21px;
}
.k-cap h3 { margin: 0; font-size: clamp(18px, 2.2vw, 22px); }
.k-qa { margin-bottom: 16px; }
.k-qa-q {
  font: 600 11px/1 var(--font-mono); letter-spacing: 1.1px; text-transform: uppercase;
  color: var(--text-400); display: block; margin-bottom: 6px;
}
.k-qa p { margin: 0; color: var(--text-300); font-size: 15.5px; }

/* Evidence items, tagged by what kind of evidence they are. */
.k-ev-list { list-style: none; padding: 0; margin: 0; }
.k-ev-list li {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 12px 0; border-bottom: 1px solid var(--border-soft);
  font-size: 15px; color: var(--text-300); line-height: 1.6;
}
.k-ev-list li:last-child { border-bottom: 0; }
/* A flex item will not shrink below its longest unbreakable word unless
   min-width is cleared. "visual/auditory/kinaesthetic" on evidence.html pushed
   the row past the viewport on a phone. */
.k-ev-list li > span:last-child { min-width: 0; overflow-wrap: break-word; }
.k-ev-tag {
  flex-shrink: 0; min-width: 84px; text-align: center;
  font: 700 9.5px/1 var(--font-mono); letter-spacing: .9px; text-transform: uppercase;
  border-radius: 100px; padding: 6px 9px; margin-top: 2px;
}
.k-ev-mechanism { color: var(--cyan); background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border-soft); }
.k-ev-research  { color: #c4b5fd; background: var(--purple-soft); border: 1px solid var(--purple-border); }
.k-ev-record    { color: var(--green); background: rgba(74,222,128,.1); border: 1px solid rgba(74,222,128,.3); }
.k-ev-list a { color: var(--cyan); text-decoration: underline; text-underline-offset: 3px; }

/* The limits of the evidence — as important as the evidence. */
.k-honest {
  margin-top: 16px; padding: 14px 16px;
  border-left: 3px solid var(--amber); background: rgba(245,158,11,.07);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
}
.k-honest p { margin: 0; font-size: 14.5px; color: var(--text-300); }
.k-honest strong { color: #fcd34d; }

/* Research entries. */
.k-res {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-md); padding: 22px; margin-bottom: 16px;
  scroll-margin-top: calc(var(--nav-h) + 20px);
}
.k-res h3 { margin-bottom: 10px; font-size: 18px; }
.k-res p { color: var(--text-300); font-size: 15px; margin-bottom: 12px; }
.k-res-applied {
  background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border-soft);
  border-radius: var(--r-sm); padding: 12px 14px; margin-bottom: 12px;
}
.k-res-applied p { margin: 0; font-size: 14.5px; color: var(--text-200); }
.k-res-src { list-style: none; padding: 0; margin: 0; }
.k-res-src li {
  font: 400 13px/1.55 var(--font-mono); color: var(--text-400);
  padding-left: 16px; text-indent: -16px; margin-bottom: 7px;
}
.k-res-caveat { border-left: 3px solid var(--amber); background: rgba(245,158,11,.07); padding: 12px 14px; border-radius: 0 var(--r-sm) var(--r-sm) 0; margin-top: 12px; }
.k-res-caveat p { margin: 0; font-size: 14px; color: var(--text-300); }

/* Changelog timeline. */
.k-log { list-style: none; padding: 0; margin: 0; }
.k-log-entry {
  position: relative; padding-left: 26px; padding-bottom: 30px;
  border-left: 2px solid var(--border-soft);
}
.k-log-entry:last-child { border-left-color: transparent; padding-bottom: 0; }
.k-log-entry::before {
  content: ""; position: absolute; left: -7px; top: 5px;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--cyan);
}
.k-log-entry.is-incident::before { border-color: var(--amber); }
.k-log-date { font: 600 11.5px/1 var(--font-mono); color: var(--text-400); letter-spacing: .5px; }
.k-log-entry h3 { margin: 8px 0 10px; font-size: 18px; }
.k-log-tag {
  display: inline-block; font: 700 9.5px/1 var(--font-mono); letter-spacing: .9px;
  text-transform: uppercase; border-radius: 100px; padding: 5px 9px; margin-left: 8px;
  color: var(--cyan); background: var(--cyan-bg-soft); border: 1px solid var(--cyan-border-soft);
  vertical-align: middle;
}
.k-log-tag.is-incident { color: var(--amber); background: rgba(245,158,11,.1); border-color: rgba(245,158,11,.3); }
.k-log-entry ul { margin: 0 0 0 0; padding-left: 20px; }
.k-log-entry li { color: var(--text-300); font-size: 15px; margin-bottom: 8px; }
.k-log-entry li::marker { color: var(--cyan); }
.k-log-note {
  margin-top: 12px; padding: 12px 14px; font-size: 14.5px; color: var(--text-400);
  background: var(--bg-elev-1); border-radius: var(--r-sm); border: 1px solid var(--border-soft);
}

/* Roadmap. */
.k-road-group { margin-bottom: 36px; }
.k-road-group > h2 { font-size: 21px; margin-bottom: 8px; }
.k-road-intro { color: var(--text-400); font-size: 15px; margin-bottom: 18px; }
.k-road-item {
  background: var(--bg-card); border: 1px solid var(--border-soft);
  border-radius: var(--r-md); padding: 16px 18px; margin-bottom: 12px;
}
.k-road-item h4 { margin-bottom: 5px; font-size: 16px; }
.k-road-item p { margin: 0; font-size: 14.5px; color: var(--text-300); }